The present invention broadly relates to a system which may be attached to, or manufactured within a television set which permits the television owner who subscribes to a particular information service, upon demand, to view on the television screen desired television programming information and subsets thereof. More particularly, the present invention permits the subscriber to controllably view at his leisure the provided updated information such that the information or desired subsets thereof may be viewed on the television either to the exclusion of the received TV signal, or as an overlay to the viewed TV program, or as a window on the screen.
Numerous television accessories, special purpose TV systems, and methods of transmitting auxiliary information to a TV receiver are known in the art. For example, U.S. Pat. No. 4,344,090 to Pietro Belisomi et al., discloses a picture display device which uses a ROM to keep coded data corresponding to a television picture in memory. The coded data is perceived as containing advertising or television operating instructions which may be viewed upon demand and which may be superimposed upon or viewed as an alternative to the received video signal. U.S. Pat. No. 4,288,809 to Yabe describes transmitting alphanumeric information during the blank field intervals of video signals. The added information is identified by an identification code and is stored in temporary memory means for display on the television. The patent further describes an index switch which permits the viewer to determine by an overlay on the screen, which alphanumeric programs are available. The index listing is contained on a RAM which may be updated by the blank field interval transmitted data.
The Insam U.S. Pat. No. 4,161,728 discloses means for displaying "Teletext" and/or "Viewdata" information; the former being information sent during field blanking of video information, and the latter being information sent from telephone. The patent describes means with a memory unit for storing information to be displayed, a display unit for synchronizing and producing addresses to memory containing the information to be displayed, a decoder unit, a control unit which is accessible through remote control, and a microprocessor which is responsive to programmed instruction. The Keiser U.S. Pat. No. 4,390,901 suggests the coding of the type of television programming which is available. The code information would be provided during the vertical blanking gap of the video signal and would be compared to the code contained in the receiver so that a video recorder could be turned on or off depending on how the viewer has programmed the same.
U.S. Pat. No. 4,052,719 to Hutt et al. describes the transmission of auxiliary information during the field blanking intervals of video signal transmission. On the receiving end, a television receiver system has a RAM for collecting and storing information, a selector, and a reading device. The stored information is fed to a character generator repeatedly after the memory is filled. The viewer has the choice of viewing the video signal or the auxiliary information separately or together on the screen. U.S. Pat. No. 4,270,145 to Farina discusses the use of an alphanumeric character generating circuit with memory and processor for controllably superimposing the time, channel, and other similar information on the video screen. The Doumit et al. U.S. Pat. No. 4,203,130 describes the display of program schedule information and other data to cable subscribers. The information is mixed into the transmission signal on the transmission end and is displayed on the entire television screen.
While all of the above-summarized patents are useful in providing additional information to the viewer, none of the patents permits the viewer to controllably view at his leisure periodically updated information regarding television programming and subsets thereof as either an overlay or window on the display of the received television signals, or as a full screen display.